Rubric Capital discloses 5.83% MannKind Corporation (MNKD) stake

Rhea-AI Filing Summary

Rubric Capital Management LP and David Rosen reported a passive ownership position in MannKind Corporation common stock. They beneficially own 18,000,000 shares, representing 5.83% of the outstanding common stock, with shared voting and dispositive power over all reported shares and no sole power. The percentage is based on 308,950,166 shares outstanding as of April 24, 2026, as stated in MannKind’s Form 10-Q. Rubric Capital Master Fund LP has the right to receive dividends and sale proceeds from more than 5% of the common stock.

Key Figures

Shares beneficially owned: 18,000,000 shares Ownership percentage: 5.83% Shares outstanding: 308,950,166 shares +3 more

6 metrics

Shares beneficially owned 18,000,000 shares Common Stock beneficially owned by Rubric Capital and David Rosen

Ownership percentage 5.83% Percent of MannKind common stock class beneficially owned

Shares outstanding 308,950,166 shares MannKind common stock outstanding as of April 24, 2026

Shared voting power 18,000,000 shares Shares over which reporting persons have shared power to vote

Sole voting power 0 shares Shares over which reporting persons have sole power to vote

Shared dispositive power 18,000,000 shares Shares over which reporting persons have shared power to dispose

Key Terms

beneficially owned, shared voting power, shared dispositive power, investment adviser, +1 more

5 terms

beneficially owned financial

"The percentage set forth in Row (11) of the cover page for each of the Reporting Persons"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

shared voting power financial

"6 | Shared Voting Power 18,000,000.00 7 | Sole Dispositive Power 0.00"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

shared dispositive power financial

"8 | Shared Dispositive Power 18,000,000.00 9 18,000,000.00"

investment adviser financial

"Rubric Capital, the investment adviser to certain investment funds and/or accounts"

An investment adviser is a person or firm that professionally manages money and gives recommendations about buying, selling, or holding investments. Like a financial coach or guide, they have a legal duty to act in a client's best financial interest, so their advice, fees and potential conflicts can directly affect returns and risk — making their role important for investors who want informed, accountable help with portfolios.

Schedule 13G regulatory

"This statement is filed by: (i) Rubric Capital Management LP"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

FAQ

What stake in MannKind Corporation (MNKD) does Rubric Capital report?

Rubric Capital reports beneficial ownership of 18,000,000 shares of MannKind common stock, representing 5.83% of the outstanding shares, based on 308,950,166 shares outstanding as of April 24, 2026.

Who are the reporting persons on this MannKind (MNKD) Schedule 13G?

The reporting persons are Rubric Capital Management LP, as investment adviser to certain funds holding MannKind shares, and David Rosen, Managing Member of Rubric Capital Management GP LLC.

What voting and dispositive power does Rubric Capital have over MNKD shares?

Rubric Capital and David Rosen report 0 shares with sole voting or dispositive power and 18,000,000 shares with shared voting and shared dispositive power over MannKind common stock.

How was the 5.83% ownership in MannKind (MNKD) calculated?

The 5.83% ownership is calculated using 308,950,166 MannKind common shares outstanding as of April 24, 2026, as reported in MannKind’s Form 10-Q for the quarter ended March 31, 2026.

Which Rubric-related fund directly benefits from MNKD dividends and sale proceeds?

The filing states that Rubric Capital Master Fund LP, a Rubric Fund, has the right to receive or direct the receipt of dividends and sale proceeds from more than 5% of MannKind’s common stock.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/14/2026 - 04:09 PM Accepted by SEC EDGAR 08/14/2026 - 04:04 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

MannKind Corporation

(Name of Issuer)

Common Stock, $0.01 par value per share

(Title of Class of Securities)

56400P706

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 56400P706

1

Names of Reporting Persons

Rubric Capital Management LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 18,000,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 18,000,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

18,000,000.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.83 %

12

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13G

CUSIP Number(s): 56400P706

1

Names of Reporting Persons

David Rosen

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 18,000,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 18,000,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

18,000,000.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.83 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: MannKind Corporation
(b)	Address of issuer's principal executive offices: 1 Casper St Danbury, CT, 06810
Item 2.
(a)	Name of person filing: This statement is filed by: (i) Rubric Capital Management LP ("Rubric Capital"), the investment adviser to certain investment funds and/or accounts (collectively, the "Rubric Funds") that hold the shares of Common Stock, $0.01 par value per share (the "Common Stock") of MannKind Corporation, a Delaware corporation (the "Issuer") reported herein; and (ii) David Rosen ("Mr. Rosen"), Managing Member of Rubric Capital Management GP LLC, the general partner of Rubric Capital. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." The filing of this statement should not be construed as an admission that any of the forgoing persons or any Reporting Person is, for the purposes of Section 13 of the Act, the beneficial owner of the Shares reported herein.
(b)	Address or principal business office or, if none, residence: The address of the principal business office of each of the Reporting Persons is 155 East 44th St, Suite 1630, New York, NY 10017.
(c)	Citizenship: Rubric Capital is a Delaware limited partnership. Mr. Rosen is a citizen of the United States of America.
(d)	Title of class of securities: Common Stock, $0.01 par value per share
(e)	CUSIP Number(s): 56400P706
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: The information required by Items 4(a) - (c) is set forth in Rows 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The percentage set forth in Row (11) of the cover page for each of the Reporting Persons and in Item 4(b) is based on 308,950,166 shares Common Stock outstanding as of April 24, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2026 filed with the Securities and Exchange Commission on May 6, 2026.
(b)	Percent of class: 5.83 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(ii) Shared power to vote or to direct the vote: The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(iii) Sole power to dispose or to direct the disposition of: The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(iv) Shared power to dispose or to direct the disposition of: The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. See Item 2(a). Rubric Capital Master Fund LP, a Rubric Fund, has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, more than 5% of the Common Stock.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Rubric Capital Management LP

Signature:	/s/ Michael Nachmani
Name/Title:	Michael Nachmani / Chief Operating Officer
Date:	08/14/2026

David Rosen

Signature:	/s/ David Rosen
Name/Title:	David Rosen / Individually
Date:	08/14/2026